One of the ads was a video called “Homosexuality was my identity” promoting gay conversion therapy, and another promoted a self-help book called “Help for Men with Same-Sex Attraction,” according to the report.

When users asked the platform “Why am I seeing this ad?” they were told they had shown an interest in “gender issues”.

“Gay conversion” or “gay cure” therapy is the dangerous and discredited practice of attempting to “change” sexual orientation using psychological or spiritual means. The practices have been widely condemned as unethical and dangerous by peak medical bodies around the world.

Facebook user Alystair Ryder said seeing the advertising had left him feeling “shaken” and it was irresponsible for Facebook to target such ads to young LGBTIQ people.

“It was written in a way to try to appeal to people who may be depressed or self loathing due to their sexuality,” he said.

“I think it’s pretty irresponsible for Facebook to allow an advert that preys on gay men with mental health issues in such a negative way on their homepage.

“I don’t think I was targeted for any specific reason, aside from being gay, but out of the people I know who I’ve asked, I’m the only person who has been targeted with this ad.”

Another user, Tessa Ann Schwartz, was angry Facebook had allowed young people to see the ads and said she had complained to Facebook.

“I don’t know why Facebook has permitted this group to target LGBT people, who have intentionally sought out community and education amongst peers, for shaming and hatred masked as love,” she told The Telegraph.

In response, Facebook blamed a glitch in its “micro-targeting” algorithm that lead to the young LGBTIQ people seeing the ads.

The company told the Telegraph it had since removed the advertising, in line with its policies that state ads mustn’t “contain content that discriminates against, harasses, provokes or disparages” users of the platform.

“Gay conversion” therapy is less prevalent in Australia than in years gone by, but still exists underground in Australia.

Conversion therapy survivor Chris Csabs started a Change.org petition calling for a national ban on the practice and has since received 42,000 signatures.

A recent survey of LGBTIQ Australians by advocacy group just.equal found a national conversion therapy ban was a top priority ahead of the next federal election.